The invention relates to a band pass filter and in particular to a band-pass filter. Such a band pass filter is for example known from "Frequenz", volume 15, pages 111-121. When varying such a band pass filter over a large frequency range, there is often a problem in maintaining constant the form of the filter response, which represents the characteristics of the band pass filter over the entire frequency range. It is of great interest when varying this over a wide frequency range that particularly the curve relative to the middle frequencies should be constant, that is the respective data of the filter, such as for example the respective band width of the transmission range.